One day I was migrating a Zabbix server database to another server and an error occurred:
Continue reading “Zabbix ERROR 1273 (HY000) at line 483: Unknown collation: ‘utf8mb4_0900_ai_ci’”Category Archives: Databases
Can’t open PID file /run/zabbix/zabbix_server.pid (yet?) after start: No such file or directory
Once, on Ubuntu 18.04.6 LTS, I updated the Zabbix server to version 6.0 LTS and the new version did not start.
Continue reading “Can’t open PID file /run/zabbix/zabbix_server.pid (yet?) after start: No such file or directory”Key ‘x’ doesn’t exist in table ‘x’
Once after updating the ABillS billing system, when opening the Maintenance>Hardware>PON menu and selecting a device, an SQL error occurred:
MySQL. Accepted a connection with deprecated protocol ‘TLSv1.1’
One day I noticed warnings in the MySQL logs:
Solution for error 21S01 Column count doesn’t match value count at row 1
Once it was necessary to make a record in the table very quickly and I quickly wrote a SQL query, but after executing it I got an error:
Continue reading “Solution for error 21S01 Column count doesn’t match value count at row 1”Solution: Specified key was too long; max key length is 767 bytes
Once on Ubuntu Server 18.04 I upgraded Zabbix 4.4 to 5.0 and found an error in the logs during the upgrade:
Continue reading “Solution: Specified key was too long; max key length is 767 bytes”How to change innodb_flush_method in MySQL
innodb_flush_method defines the method for flushing data from RAM to disk.
Continue reading “How to change innodb_flush_method in MySQL”Migrating MySQL Directory
Once I created a raid, mounted it as a disk system partition and transferred the MySQL directory directly to it, but in this case there were drawbacks, the lost+found directory could appear, it could not be used for other data, etc., after that I began to transfer the MySQL directory not directly to the partition, but created a directory on it and transferred it to it.
Continue reading “Migrating MySQL Directory”How to change innodb_io_capacity in MySQL
innodb_io_capacity – determines the number of write IOPS for background InnoDB tasks, such as flushing pages from a buffer pool, etc. If the cleanup operation is lagging, then InnoDB can perform cleanup more aggressively at a higher IOPS, which is defined in the innodb_io_capacity_max variable.
Continue reading “How to change innodb_io_capacity in MySQL”Partitioning tables in MySQL
Partitioning tables in MySQL is splitting a large table into parts according to the specified criteria, which will speed up reading and writing data to it if this table contains a very large amount of data.
Continue reading “Partitioning tables in MySQL”